Physicochemical and nutraceutical properties of tomato powder as affected by pretreatments, drying methods, and storage period

Abstract

ABSTRACT This study was carried out to evaluate the effect of different pretreatments, drying methods, and storage period on physicochemical and nutraceutical properties of tomato powder. The results revealed that freeze-dried tomato powder showed significantly (p < .05) higher ash, total sugar, reducing sugar, ascorbic acid, lycopene, β-carotene, lightness (L*), redness (a*), and yellowness (b*) values than hot-air-dried samples. However, pH, titratable acidity, and TSS (oBx) showed non-significant difference (p > .05) between hot-air- and freeze-dried samples. Comparing the different pretreatments sodium metabisulphite 1% treated sample (T2) showed highest total sugar, reducing sugar, rehydration ratio, TSS (oBx), lightness (L*), redness (a*) and yellowness (b*) values than non-pretreated samples (T0) and 0.5% ascorbic acid + 0.5% citric acid-treated samples (T1). While T1 showed the highest ascorbic acid, lycopene, and β-carotene contents than T2 and T0. The results obtained indicated that TSS (oBx), pH, total sugar, reducing sugar, rehydration ratio, ascorbic acid, β-carotene, lycopene, and color parameters (L*, a,* and b*) of both freeze-dried and hot-air dried powdered samples showed decreasing trend, while moisture and titratable acidity showed an increasing trend with the advancement of storage period from 0 to 30 days.